Fast Math | Vedic Mental Math Tricks - Cubes 01 | Don't Memorise | Summary and Q&A

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October 17, 2016
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Infinity Learn NEET
Fast Math | Vedic Mental Math Tricks - Cubes 01 | Don't Memorise

TL;DR

Learn a fast and efficient method to calculate the cube of a number by using its tens and units digits.

Key Insights

• 👂 This technique relies on the observation of the tens and units digits to determine the digits of the cube.
• 👂 The cube of the tens digit is written in the first column and multiplied by subsequent digits.
• ✖️ The numbers in the second and third columns are always multiplied by two, resulting in a consistent pattern.
• 🪜 Adding the numbers in each column vertically yields the final result.
• 🧊 This technique is derived from the cube of a binomial identity, modified for quick calculation.
• 🧊 The same method can be applied to other numbers to calculate their cubes efficiently.
• 🐎 Practice and familiarity with the technique can enhance speed and accuracy in cube calculations.

Transcript

how do we find the cube of a number really fast say we have to find the cube of 12 the first thing we have to do is observe the units and the 10th digit of the number that is being cubed the 10th digit is one and the unit's digit is two then we ask ourselves one question 10th digit multiplied by what will give us the units digit yes what do we mult... Read More

Q: What is the first step in finding the cube of a number using this technique?

The first step is to observe the tens and units digits of the number being cubed. These digits play an important role in determining the digits of the cube.

Q: How are the digits of the cube calculated using this technique?

The cube of the tens digit is written in the first column. It is then multiplied by the tens digit, and the result is multiplied by the units digit. This process continues for subsequent columns, each time multiplying by the next digit.

Q: What is the significance of the number "2" in this technique?

The numbers in the second and third columns are always multiplied by two. This constant multiplication by two allows for a quick and consistent calculation method.

Q: How is the final result obtained using this technique?

Once all the columns are calculated, including the second and third columns multiplied by two, the numbers in each column are added vertically to obtain the final result.

Summary & Key Takeaways

• The technique involves observing the tens and units digits of the number being cubed and using multiplication to find the digits of the cube from left to right.

• The cube of the tens digit is written in the first column and multiplied by the tens digit, then by the units digit, and so on.

• The numbers in the second and third columns are always multiplied by two, and the columns are added to obtain the final result.